Re: Xray exposure

[Kleat1@aol.com]

In a message dated 6/11/1999 11:17:40 AM Eastern Daylight Time, 
dsimpkin@execpc.com writes:

<< dsimpkin@execpc.com >>

Doug:

Thank you for responding to my request for Technique Chart information. What 
I am attempting to do is come up with an mR reading that will put me in a 
range of a diagnostically acceptable films for a given body part thickness -- 
kind of like working a problem backwards from an answer.  

The problem I am trying to address is the lack of consistency in radiation 
readings one gets at any given setting (80 kVp 100 mA @ 1/10 sec.) from one 
x-ray machine to another.  For the most part its a calibration / equipment 
problem.  I would like to ultimately be able to normalize other x-ray 
machines to x-ray equipment that have been set up and are being used 
routinely by qualified personnel in the healing arts profession to produce 
diagnostically acceptable x-rays. Acceptable x-rays are x-ray that are deemed 
acceptable by a Radiologist or a Registered X-ray Technician.  I'm hoping 
this kind of data is available. 

 X-ray Technicians can and do adjust their techniques to compensate for these 
differences but, all the have to go by is a kVp setting knob, and a mA knob 
and a time knob to control the x-ray beam and exposure they are applying to 
the patient to produce an x-ray. 

I am looking for data (mR readings from a calibrated instrument) collected 
from an x-ray machine, where the kVp has been measured and verified to be 
within specified limits from the machine dial settings at 50 to 110 kVp. 
Other Information such as the film/screen combination in use and the grid 
ratio on the machine would also be helpful.

I'll check with the JCAHO to see what is required at hospitals. I'm under the 
impression they focus on the radiation exposure that the patient received for 
the x-ray taken. Their interest is in dose -- my interest is in film quality. 
 

 In the meantime time I'll use the information you provided as a start.  By 
looking at the chart you provided I'm going to assume a film speed of 400 and 
a grid ratio of 10 to 1.

Thanks again for the help.

Kenneth Travis

Kleat1@oal.com

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